1. Field of the Invention
The present invention relates to an actuator for a circuit breaker and a fabrication method thereof, and more particularly, to an actuator for a circuit breaker capable of simplifying the structure, reducing the fabrication cost and preventing the performance of a device from being deteriorated due to an external shock, and a fabrication method thereof.
2. Description of the Related Art
As an apparatus used to provide a linear movement in a mechanical apparatus such as a circuit breaker, a refrigerator compressor or the like, and control a switching operation on a portion at which the switching of a contact point is carried out, an actuator can be divided into a mechanical type and an electronic type according to a control method of its switching operation.
An actuator for a circuit breaker in the related art is illustrated in FIG. 1, and a schematic cross-sectional view of a body portion constituting an actuator in the related art is illustrated in FIG. 3, and a schematic view showing the path of a main magnetic path formed within an actuator for a circuit breaker in the related art is illustrated in FIG. 3, and a schematic view showing the path of an auxiliary magnetic path formed within an actuator for a circuit breaker in the related art is illustrated in FIG. 4.
As illustrated in FIGS. 1 through 4, an actuator in the related art may include a body portion 30 in which each constituent element is provided thereinside, an upper cover 10 configured to cover an upper portion of the body portion 30, and a lower cover 20 configured to cover a lower portion of the body portion 30, and the like.
Here, an inside of the body portion 30 may include a wound coil 33, a permanent magnet 37 located adjacent to the coil 33, a stationary core 41 provided between the wound coil 33, a movable core 43 brought into contact with or separated from the stationary core 41, an operating rod 45 allowing the movable core 43 to be brought into contact with or separated from the stationary core 41, an elastic member 40 configured to provide an elastic force to the operating rod 45, a first yoke 31 located in the vicinity of the wound coil 33 to form a main magnetic path, a second yoke 35 configured to form an auxiliary field in a downward direction, a first magnetic force adjustment plate 39 and a second magnetic force adjustment plate 47, and the like.
According to an actuator for a circuit breaker having the foregoing configuration, when a current is applied to each coil 33, a magnetic flux is generated through the coil 33, and a main magnetic path 50 is formed through the first yoke 31, the stationary core 41 and the movable core 43 surrounding the coil 33 while at the same time forming an auxiliary magnetic path 60 through the second yoke 35 or the like, and a magnetic force is generated between the stationary core 41 and the movable core 43 through the main magnetic path 50 and auxiliary magnetic path 60, thereby allowing the movable core 43 to be brought into contact with the stationary core 41.
Furthermore, when the current is blocked, the magnetic force disappears, and the movable core 43 brought into contact with the stationary core 41 receives an elastic restoring force through the elastic member 40 thereby allowing the movable core 43 to be separated from the stationary core 41.
On the other hand, a magnetic strength of the main magnetic path and auxiliary magnetic path is controlled through the first magnetic force adjustment plate 39 and the second magnetic force adjustment plate 47.
However, an actuator for a circuit breaker in the related art having the foregoing configuration may use the upper cover 10 and lower cover 20 to fix the second yoke 35 for forming the auxiliary magnetic path 60, and thus has a problem in which the second yoke 35 cannot be securely fixed.
Furthermore, the upper cover 10 and lower cover 20 may be used therein, and thus has a problem of increasing the volume of the actuator as well as increasing the fabrication cost and increasing a time consumed for fabrication.
Furthermore, since the second yoke 35 is not securely fixed, the second yoke 35 may be shaken or the location of the second yoke 35 may vary while using the actuator to change a magnetic force delivered to the stationary core 41 and movable core 43 through the auxiliary magnetic path 60, and thus has a problem in which the stationary core 41 and movable core 43 are separated from each other in a conducting state.